Refrigerant circuit for refrigerating systems



April 10, 1934. w GARLAND 1,954,695

REFRIGERANT CIRCUIT FOR REFRIGERATING SYSTEMS Filed Dec. 27, 1930 Q3 m Qm I N 1 k m m gvvuz'nto'o I H M g MiltonWG'arland s m M q ,7

Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE REFRIGERANT CIRCUITFOR REFRIGERAT- ING SYSTEMS Milton W. Garland, Waynesboro, Pa., assignorto Frick Company, Waynesboro, Pa., a corporation of Pennsylvania Thisinvention relates to means for circulating refrigerant fluid through anevaporator of a refrigerating system.

The object of the invention is to provide means 5. for returning liquidor unevaporated refrigerant from an accumulator back to the evaporatorand to utilize the force of gravity to overcome the pressure in theevaporator.

A further object is to provide means for con- E1 trolling the passage ofliquid refrigerant to the evaporator in response to variations of theliquid level in the accumulator.

Referring to the accompanying drawing, which is made a part hereof andon which similar refer- 1'5 ence characters indicate similar parts.

Figure l is a side elevation of a system showing my invention embodiedtherein, and

Figure 2, a modified form of float control.

In the drawing reference numeral indicates a freezing tank having anevaporator therein, the evaporator comprising upper and lower headers 11and 12 connected by riser tubes 13, only one of which is shown. Theriser tubes 13 may be of any suitable shape, W tubes such as shown he-;ing found one preferred form A line 14 connects one end of the upperheader with an accumulator 15. A suction line 16 from the accumulator isconnected to the suction of the compressors not shown. Liquidrefrigerant is de- ;livered to the evaporator through a line 17connected to one end of the lower header 12. An oil drain 18 may beconnected at the other end of the lower header. Liquid refrigerant froma suitable source is supplied to the system through ';line 19 through astrainer 20, a float controlled valve 21, a line 22 and a line 23 to theline 17., The valve 21 is controlled by a float in a tank 24, the valvebeing opened when the liquid in the tank 24 reaches a predetermined lowlevel. A booster line 25 controlled by valve 30 may be connected aroundthe float control valve 21. The bottom of the accumulator is connectedto the line 17 by means of a pipe 26. Equalizing pipes 2'7 and 28connect the bottom of the tank 24 with o the line 26 and the top of thetank 24 with the accumulator 15. An oil drain valve 29 may be connectedto the bottom of the accumulator.

In operation liquid refrigerant is first delivered to the system throughthe line 19 until 9 ;the evaporator is flooded. During operation gasdrawn through the pipe 14 into the accumulator will carry over a certainamount of liquid along with it, depositing the liquid into theaccumulator 15. This liquid refrigerant returns to the evappratorthrough the line 26 and pipe 17. The accumulator is positioned above theevaporator so that the liquid refrigerant which is carried over into theaccumulator may freely flow by gravity to the evaporator against suchpressure as is in the evaporator. Because of equalizing pipes 27 and 28the level of liquid in tank 24 is the same as that in return pipe 26.The float controlled valve 21 is so arranged that as soon as the liquidin the tank 24 lowers the valve 21 will operate and supply additionalliquid refrigerant to the evaporator coils. This system is particularlyadvantageous when applied to coil type evaporators where highevaporation causes entrained unevaporated liquid to be carried alongwith the suction gas into the accumulator where operating andtemperature head in the evaporator do not permit the entrained liquid inthe suction line to return to the evaporator without some pressuresupplying means. In this instance the pressure is supplied by gravity sothat the liquid from the accumulator will flow into the evaporatoragainst such pressure head as may be therein.

In the modified form shown in Figure 2 the controlling float 31 ispositioned in the accumulator 32 itself. This float controls a valve 33in the liquid refrigerant supply line 34 so that as the liquid level inthe accumulator falls additional liquid refrigerant will be delivered tothe evaporator.

It will be obvious to those skilled in the art that various changes maybe made in my device without departing from the spirit of the inventionand therefore I do not limit myself to what is shown in the drawing anddescribed in the specification, but only as indicated by the appendedclaims.

Having thus fully described my said invention, what'I claim as new anddesire to secure by Letters Patent, is:

1. In a refrigerating system an evaporator, an accumulator positioned ata greater elevation than the evaporator whereby liquid may flow bygravity to the evaporator, a suction line from the evaporator to theaccumulator and a liquid supply line from the accumulator to theevaporator, a float chamber connected to the accumulator and to thesupply line to the evaporator to equalize the liquid level in the saidsupply line and in the said chamber, a liquid supply line to theevaporator, a valve for said line, a float in said chamber in control ofthe said valve, substantially as set forth.

2. In a refrigerating system an evaporator, an accumulator positionedat. a higher elevation than the evaporator, a suction line from theevaporator to the accumulator, a liquid supply line from the accumulatorto the evaporator to return liquid refrigerant to the evaporator, aliquid refrigerant feed line for supplying additional liquid refrigerantto the evaporator, a float chamber communicating with the accumulatorand with the liquid supply line from the accumulator to the evaporatorto equalize the liquid level in the chamber and in the said liquidsupply line, a valve in the feed line for supplying additional liquidand a float in the said chamber in control of said valve, substantiallyas set forth.

3. In a refrigerating system an evaporator, an accumulator positioned at.a higher elevation than the evaporator, a suction line from theevaporator to the accumulator, a liquid supply line from the accumulatorto the evaporator to return liquid refrigerant to the evaporator, aliquid refrigerant feed line for supplying additional liquid refrigerantto the evaporator, a float chamber communicating with the accumulatorand with the liquid supply line from the accumulator to the evaporatorto equalize the liquid level in the chamber and in the said liquidsupply line, a

valve in the feed line for supplying additional liquid and a float inthe said chamber in control of said valve, said valve being opened upona reduction of the liquid level in the chamber and closed upon a rise inthe liquid level, substantial- IV as set forth.

4. In a refrigerating system an evaporator, an accumulator positionedwith respect to the evaporator so as to cause liquid to flow by gravityfrom the accumulator to the evaporator, a suction line from theevaporator to the accumulator, a liquid return line from the accumulatorto the evaporator, an auxiliary liquid supply line to the evaporator, avalve in said line, a float chamber communicating with the accumulatorand a liquid line from the accumulator to the evaporator for equalizingliquid level in the chamber and in the return line, a float in saidchamber in control of; the valve for supplying additional liquid to theevaporator, said float being responsive to variations in the flow ofliquid from the accumulator to the evaporator, substantially as setforth.

MILTON W. GARLAND.

